Nitrogen at relatively high purities is finding increasing usage in such applications as for blanketing, stirring or inerting purposes in such industries as glass and aluminum production, and in enhanced oil or natural gas recovery. Such applications consume large quantities of nitrogen and thus there is a need to produce relatively high purity nitrogen at high recovery and at relatively low cost.
Capital costs are kept low by avoiding the need to employ a full scale double column air separation process. Operating costs are reduced by energy efficient operation. Since a large part of the power required by the air separation process is consumed by the feed air compressor, it is desirable to recover as product as much of the feed air as is practical.
It is therefore an object of this invention to provide an improved air separation process for the cryogenic distillative separation of air.
It is another object of this invention to provide an improved air separation process for the cryogenic separation of air which can produce nitrogen at relatively high purity and relatively high yield.
It is a further object of this invention to provide an improved air separation process for the cryogenic separation of air which can produce nitrogen at relatively high purity and relatively high yield while avoiding the need to employ a full scale double column.